Currently, a photovoltaic device, a plasma display, an organic light emitting diode, an AMOLED (Active Matrix/Organic Light Emitting Diode), or the like, need to be sealed by using a glass adhesive. In a packaging process, in the case that the glass adhesive is sintered by a laser beam irradiated thereon, due to a non-uniform distribution of energy received by the glass adhesive, a packaging performance of the glass adhesive is reduced. For example, in a related art, the glass adhesive is sintered using a laser for outputting a laser beam focused into a circular spot. A width of the glass adhesive may be slightly less than a diameter of a laser spot. Since a position closer to a center of the glass adhesive is scanned by the laser spot for a longer time than a position of an edge of the glass adhesive, a heat quantity received in a central region of the glass adhesive is greater than that received in an edge region. In this way, the glass adhesive at the edge region cannot effectively melt for bonding, or the glass adhesive is over sintered due to excessive energy at the center region of the glass adhesive, and the packaging performance of the glass adhesive is decreased. In addition, since the energy at the center region is higher than that at the edge region, a non-uniform stress distribution is generated due to a non-uniform heat distribution inside the glass adhesive, thereby causing a reduction in mechanical strength of an OLED (Organic Light Emitting Display) device.